New softnose skate genus Brochiraja from New Zealand (Rajidae: Arhynchobatinae) with description of four new species

Brochiraja, a new rajid genus, is defined for a group of softnose skates from the deep sea adjacent New Zealand. The group presently contains six species: Brochiraja asperula (Garrick & Paul), B. spinifera (Garrick & Paul), and four new taxa, B albilabiata sp. nov., B. aenigma sp. nov., B. leviveneta sp. nov., and B. microspinifera sp. nov. These species are closely related to members of the Indo-Pacific genus Notoraja but three of them differ from all other softnose skates (arhynchobatins) in at least one presumed synaphomorphy-the presence of a bifurcated thorn on the mid-distal rostral cartilage that is strongly evident in juveniles and variably reduced in adults. Placement of B. aenigma, known only from the post-juvenile holotype, lacks these thorns so its placement in the genus is provisional. The new species differ from B. asperula, B. spinifera, and each other, in coloration, morphometrics, squamation, and vertebral and pectoral-fin counts. The existence of multiple morphotypes of the two pre-existing nominal taxa suggests that the New Zealand skate fauna has vicariated from populations isolated from each other on the remote continental slopes, seamounts, and plateaus of the South-West Pacific.